1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

A simple log question

  1. Jul 2, 2005 #1
    This question should be easy to most people here and need some help on this question.

    3log25 - log34 + log2(log39)

    My answer to this question is:
    = 3log25 - log34 + log2(log9/log3)
    = log2125 - log34 + log22
    = log2125 - log34 + 1
    = (log125 / log2) - (log4 / log3) + 1
    = 6.703924778

    However the correct answer give is 6.335, which means my answer is wrong. Can somebody tell me what's wrong with my answer and what should I do to get the correct answer? :frown:

    Thanks :)
    Last edited: Jul 2, 2005
  2. jcsd
  3. Jul 2, 2005 #2


    User Avatar
    Science Advisor
    Homework Helper

    These steps you have made do not make any sense:

    [tex]\log_2 \log_2 9 \Rightarrow \log_2 \left( \frac{\log 9}{\log 3} \right) \Rightarrow \log_2 2[/tex]
  4. Jul 2, 2005 #3
    opps...sorry. i had a typo in my post. edited it

    it should be:
    [tex]\log_2 \log_3 9 \Rightarrow \log_2 \left( \frac{\log 9}{\log 3} \right) \Rightarrow \log_2 2[/tex]

    but i still cannot solve this equation. :(
  5. Jul 2, 2005 #4


    User Avatar
    Science Advisor
    Homework Helper

    Well in that case your reduction of the logs is perfectly correct and your approximation to the number in decimal places is also correct. The number is about:

Share this great discussion with others via Reddit, Google+, Twitter, or Facebook